The present invention relates to the use of tapered adapters for fitting bearings, pulleys, sheaves and the like to shafts, and more particularly to an improved method and apparatus for removing a bearing assembly or the like from a shaft secured through a tapered adapter. While other devices are contemplated, a bearing assembly is utilized in the specification for illustrative purposes.
It is well known in the art to employ split tapered adapters to secure bearings, pulleys, sheaves and the like to shafts. Generally, the tapered adapter is received about a shaft and has a tapered outer surface with threads on the smaller end. The bearing assembly has a tapered bore and is forced up the adapter by tightening a locknut a nut that is threaded on the threads of the adapter. This closes the adapter around the shaft and into the bearing bore until there is a metal to metal fit between the shaft, adapter and bearing assembly. Further tightening of the locknut forces the bearing up the adapter taper expanding the inner ring of the bearing to the equivalent of several thousands of an inch press fit. The inner ring thus has a tight fit with the resulting high pressure against the adapter. The result of the high pressure, low angle of taper on the adapter and the coefficient of friction of steel on steel results in high force required to remove the bearing. In addition, fretting corrosion often develops at the bearing bore/adapter interface further increasing the force required to remove the bearing.
Since there is no convenient way to apply force from the shaft to the bearing face, it is frequently necessary to destroy the bearing and damage or risk damage to the shaft during repairs to a system. Since the shafts are not of a single diameter and are of varying lengths, the use of standard removal tools such as gear pullers is not practical. During field service, the use of a cutting torch is commonly used to remove the bearing, thus completely destroying the bearing and possibly the shaft.